The product is produced from a settable aqueous calcium sulphate dispersion which has a water to solids ratio of less than 0.4 to 1, and has distributed therethrough lightweight hollow bodies having water-impervious surfaces (such as expanded polystyrene beads). The dispersion contains a hydratable cement (such as calcium sulpho aluminate) which is capable of hydration in the presence of the calcium sulphate dispersion. The hydratable cement is such that it reacts with excess water in the dispersion thereby enhancing the water resistance of the resulting product.

The product is produced from a settable aqueous calcium sulphate dispersion which has a water to solids ratio of less than 0.4 to 1, and has distributed therethrough lightweight hollow bodies having water-impervious surfaces (such as expanded polystyrene beads). The dispersion contains a hydratable cement (such as calcium sulpho aluminate) which is capable of hydration in the presence of the calcium sulphate dispersion. The hydratable cement is such that it reacts with excess water in the dispersion thereby enhancing the water resistance of the resulting product.

The present invention relates to fiber cement products comprising an inner core material, which inner core material is covered by at least one outer surface layer, characterized in that: —said inner core material has a density of between about 0.4 and about 0.9 g/cm.sup.3 inclusive, and at least comprises cement and between 1 wt % and 70 wt % (with respect to the total dry weight of said inner core material) of a lightweight filler, and—said at least one outer surface layer has a density of between about 0.9 and about 1.4 g/cm.sup.3 inclusive, and at least comprises fibers and cement.

The present invention relates to fiber cement products comprising an inner core material, which inner core material is covered by at least one outer surface layer, characterized in that: —said inner core material has a density of between about 0.4 and about 0.9 g/cm.sup.3 inclusive, and at least comprises cement and between 1 wt % and 70 wt % (with respect to the total dry weight of said inner core material) of a lightweight filler, and—said at least one outer surface layer has a density of between about 0.9 and about 1.4 g/cm.sup.3 inclusive, and at least comprises fibers and cement.

An insulating material, in particular a permeable fire-proof insulating material comprising water glass and polystyrene, consisting of a hardening mixture which contains 1 to 32.4 wt % of expanded polystyrene, 57.5 to 96.0 wt % of aqueous sodium silicate solution, 2 to 6 wt % of aluminium hydroxide, 0.8 to 2.6 wt % water glass hardener and 0.1 to 0.5 wt % of water glass stabilizer, while the surface of the expanded polystyrene is provided with carbon black, the carbon black making up 0.1 to 1 wt % of total weight. A method for the production of insulating material, in particular a method for the production of permeable fire-proof insulating material comprising water glass and polystyrene, according to which firstly the polystyrene beads are mixed with an aqueous solution of carbon black so as to coat their entire surface, then is added to the aqueous sodium silicate solution aluminium hydroxide and the whole is mixed so as to form an insulating mixture, and then a water glass stabilizer is added to the aqueous sodium silicate solution, and then to this solution is mixed water glass hardener, with this solution being further stirred for 1 to 10 minutes to form a binder solution, and the insulating mixture is added to the binder solution with constant stirring, and the whole is mixed, and the resulting mixture is then poured into the application site.

An insulating material, in particular a permeable fire-proof insulating material comprising water glass and polystyrene, consisting of a hardening mixture which contains 1 to 32.4 wt % of expanded polystyrene, 57.5 to 96.0 wt % of aqueous sodium silicate solution, 2 to 6 wt % of aluminium hydroxide, 0.8 to 2.6 wt % water glass hardener and 0.1 to 0.5 wt % of water glass stabilizer, while the surface of the expanded polystyrene is provided with carbon black, the carbon black making up 0.1 to 1 wt % of total weight. A method for the production of insulating material, in particular a method for the production of permeable fire-proof insulating material comprising water glass and polystyrene, according to which firstly the polystyrene beads are mixed with an aqueous solution of carbon black so as to coat their entire surface, then is added to the aqueous sodium silicate solution aluminium hydroxide and the whole is mixed so as to form an insulating mixture, and then a water glass stabilizer is added to the aqueous sodium silicate solution, and then to this solution is mixed water glass hardener, with this solution being further stirred for 1 to 10 minutes to form a binder solution, and the insulating mixture is added to the binder solution with constant stirring, and the whole is mixed, and the resulting mixture is then poured into the application site.

An insulating material, in particular a permeable fire-proof insulating material comprising water glass and polystyrene, consisting of a hardening mixture which contains 1 to 32.4 wt % of expanded polystyrene, 57.5 to 96.0 wt % of aqueous sodium silicate solution, 2 to 6 wt % of aluminium hydroxide, 0.8 to 2.6 wt % water glass hardener and 0.1 to 0.5 wt % of water glass stabilizer, while the surface of the expanded polystyrene is provided with carbon black, the carbon black making up 0.1 to 1 wt % of total weight. A method for the production of insulating material, in particular a method for the production of permeable fire-proof insulating material comprising water glass and polystyrene, according to which firstly the polystyrene beads are mixed with an aqueous solution of carbon black so as to coat their entire surface, then is added to the aqueous sodium silicate solution aluminium hydroxide and the whole is mixed so as to form an insulating mixture, and then a water glass stabilizer is added to the aqueous sodium silicate solution, and then to this solution is mixed water glass hardener, with this solution being further stirred for 1 to 10 minutes to form a binder solution, and the insulating mixture is added to the binder solution with constant stirring, and the whole is mixed, and the resulting mixture is then poured into the application site.

The present invention is directed to processes for making cementitious construction material, in particular magnesium oxychloride (MOC) cementitious construction material (e.g., MOC boards). The processes relate to one or more operations of the overall material production process, including material storage and handling, mixing of materials, curing to form magnesium oxychloride cement, board handling, and/or packaging. Various processes of the present invention involve process control strategies and/or algorithms to provide improved processes for producing construction material. In particular, the processes of the present invention provide improvements in board properties as detailed below (e.g., racking strength), speed of board production, economics of board production, reduction in complexity of manufacture, improvements in consistency of board manufacture, and improvements in quality control.

The present invention is directed to processes for making cementitious construction material, in particular magnesium oxychloride (MOC) cementitious construction material (e.g., MOC boards). The processes relate to one or more operations of the overall material production process, including material storage and handling, mixing of materials, curing to form magnesium oxychloride cement, board handling, and/or packaging. Various processes of the present invention involve process control strategies and/or algorithms to provide improved processes for producing construction material. In particular, the processes of the present invention provide improvements in board properties as detailed below (e.g., racking strength), speed of board production, economics of board production, reduction in complexity of manufacture, improvements in consistency of board manufacture, and improvements in quality control.

In the present invention, a multi-stage foam sound-absorbing black body material is provided for the first time. A graphene aerogel is introduced into a commercialized polymer foam skeleton by using a solvent plasticizing and foaming technology, so as to embed ultra-thin graphene drums in the foam skeleton. When sound waves enter the foam black body, a large number of graphene drums generate a severe resonance effect, thereby rapidly achieving attenuation of the sound waves, and combined with the friction loss of the porous structure of the polymer foam on the sound waves, excellent sound-absorbing performance is achieved in a wide frequency range. The present solution is provided on the basis of commercialized foam materials, has a simple method, low costs, and the potential of wide industrial application.